The present invention relates generally to a device and system for allowing analysis of gas volumes of less than one milliliter and more particularly to a system for obtaining small gas samples from sealed packages and analyzing ultra-small volumes.
In order to protect semiconductor chip devices from environmental hazards, device manufacturers have developed a variety of ways for hermetically encapsulating integrated circuit or discrete devices. Many of these techniques rely on adhesive, anodically bonded glass or low-temperature solder for low temperature sealing of a cover to a printed wiring board of a substrate including integrated circuits or discrete devices.
Hermetic encapsulation is required for a number of semiconductor devices. In particular, MEMS (microelectromechanical system) devices require hermetic sealing to ensure a long lifetime for the moving mechanical parts within them. Furthermore, this sealing may require the inclusion of getters and/or desiccants, without adversely affecting either the sealing or the getters and/or desiccants, to improve the mechanical or other reliability. Typical MEMS hermetic encapsulating techniques are awkward and costly. Consequently, the cost of MEMS hermetic encapsulation is comparable to or can exceed the cost of the fabrication of the MEMS wafer. Current techniques, as previously described, utilized for hermetic encapsulation of MEMS devices include soldering, eutectic metal bonding, and wafer fusion. It is therefore important that these MEMS packages be evaluated to ensure hermeticity. This is generally performed by selecting a sub-set sampling of packages that is statistically representative of a lot of produced MEMS packages and testing the sub-set of packages for hermeticity by performing a residual gas analysis on each package to determine if leakage has occurred. For example, if a MEMS package is hermetically sealed using nitrogen gas, the MEMS package can be destructively tested to determine if the gas inside the package contains any impurities that indicate a lack of hermeticity.